employed . it was originally discovered by ivan nikola ##evich na ##zar ##ov ( 1906 – 1957 ) in 1941 while studying the rear ##rang ##ement ##s of ally ##l vinyl ke ##tones . as originally described , the na ##zar ##ov cy ##cl ##ization involves the activation of a di ##vin ##yl ke ##tone using a st ##oic ##hi ##ometric lewis acid or pro ##tic acid promoter . the key step of the reaction mechanism involves a cat ##ion ##ic 4 ##π @ - @ electro ##cy ##cl ##ic ring closure which forms the cy ##cl ##open ##ten ##one product ( see mechanism below ) . as the reaction has been developed , variants involving substrates other than di ##vin ##yl ke ##tones and promoters other than
employed. it was originally discovered by ivan nikolaevich nazarov ( 1906 – 1957 ) in 1941 while studying the rearrangements of allyl vinyl ketones. as originally described, the nazarov cyclization involves the activation of a divinyl ketone using a stoichiometric lewis acid or protic acid promoter. the key step of the reaction mechanism involves a cationic 4π @ - @ electrocyclic ring closure which forms the cyclopentenone product ( see mechanism below ). as the reaction has been developed, variants involving substrates other than divinyl ketones and promoters other than